An Airbus A320 en route from San Diego to Denver experienced total hydraulic failure Wednesday morning but landed safely at Denver International Airport.

United Airlines Flight 418 landed on Runway 34-L at 11:35 a.m. and had to be towed, said Allen Kenitzer, spokesman for the Federal Aviation Administration in Seattle. No injuries were reported.

He said the FAA will investigate.

DIA spokesman Chuck Cannon said an alert was declared and fire equipment was stationed along the runway as a precaution.

Evergreen aviation consultant Mike Boyd said that what happened was serious. But he said the Airbus A320 is such an advanced aircraft and United pilots so well-trained that the passengers were never in danger.

The aircraft has backup systems, said Boyd, and the United pilots would have repeatedly faced this situation in their simulator training.

Boyd said the maneuverability of the A320 would have been limited and required the pilots to land quickly. He added that the people with a giant headache will be the mechanics who now have to repair the A320.

As news of the deadly mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, unfolded last week, Pia Guerra, a 46-year-old Vancouver-based artist, felt helpless. She couldn’t bring herself to go to sleep, so she began to draw.

Police who find suspected drugs during a traffic stop or an arrest usually pause to perform a simple task: They place some of the material in a vial filled with liquid. If the liquid turns a certain color, it’s supposed to confirm the presence of cocaine, heroin or other narcotics.